setup: add a test for running setup.py `python3 -m pip install hg-evolve==9.2.0` currently fails, despite 9.2.0 being the first beta py3 release, because of unicode issues with the version number. `setup.py install` is a proxy test for pip install since it also suffers from similar, however the test currently fails due to running setup.py from a different directory to the one it is in. Also add a test for `hg version -v` with evolve enabled since a naive first solution for the pip issue was to just change `__version__` to a `u''` string, but that busts version display in `version -v`, which isn't currently picked up by tests.

#!/bin/bash
set -euox pipefail

unset GREP_OPTIONS
NOTOPIC="--config experimental.topic-mode=ignore"

compatbranches=`hg branches --quiet | grep 'mercurial-' | grep -v ':' | sort -n --reverse`
prev='stable'
for branch in $compatbranches; do
    hg up $branch
    hg merge $prev
    hg commit -m "test-compat: merge $prev into $branch"
    prev=$branch
done